Tracking errors do occur sometimes, not depending on hardware. This is quite normal. There are a number of ways to fix them. One that is used more often is:
- find a frame after error where the actor's pose is good visible
- manually adjust the model to roughly fit the actor (you can copy the pose from one of the previous good frames to do less work)
- hit "Refit Pose"
- if there is an error again, adjust the pose more accurate or choose another frame and repeat the above steps
- once you have a correct pose, hit "Track Backward" to correct the erroneous frames
Once you get used to it, it's a really simple procedure.